1. Technical Field
The present invention relates to an object detecting apparatus.
2. Related Art
There have been proposed mechanisms for the purpose of enhancing security such as prevention of leakage of classified information, personal information, and the like, prevention of forgery of valuable securities, or prevention of theft of articles (refer to Japanese Published Unexamined Patent Application No. 2003-182847, and No. 2008-020346).
For example, a magnetic wire is provided to an object serving as an object to be detected (called a detecting object) such as a recording paper or the like. Exciting coils and detecting coils are provided to a gate for managing a passage of the object. When the detecting object goes into the gate, an alternating magnetic field generated by the exciting coils provided to the gate causes magnetization reversal in the magnetic wire provided to the detecting object. A rapid magnetic pulse according to the magnetization reversal is detected by the detecting coils of the gate, to detect the object going into the gate.
In the mechanism described in Japanese Published Unexamined Patent Application No. 2003-182847, a magnetic marker provided to a detecting object includes a magnetic wire causing rapid magnetization reversal when an alternating magnetic field is applied thereto, and an ON/OFF control element that generates a bias magnetic field capable of inhibiting magnetization reversal. Magnetic markers are turned into an on-state when detecting objects are received by a store, and a magnetic marker of a paid detecting object is turned into an off-state. When magnetization reversal of a magnetic marker is detected when a detecting object passes through an exit gate, it is determined that the detecting object is an unpaid detecting object.
In the mechanism described in Japanese Published Unexamined Patent Application No. 2008-020346, waveforms (called disturbance waveforms) of envisioned disturbance sources (noise sources) such as notebook-type personal computers (called notebook personal computers) or steel cans composed of metal materials, are stored in advance. Then, by carrying out an arithmetic operation of a detection signal waveform and the stored respective disturbance waveforms, even when a person passing through the gate having a detecting object to which a magnetic wire is provided and a disturbance source together goes into the gate, it is possible with high precision to detect a signal from the magnetic wire more than the mechanism in Japanese Published Unexamined Patent Application No. 2003-182847.